1. Make marinade: Stir together chicken, onion, garlic, salt, and pepper in a medium bowl until chicken is coated. Cover the bowl with plastic wrap and refrigerate, 4 hours to overnight.

2. Heat oil in a deep fryer or large saucepan to 340 degrees F (171 degrees C).

3. While oil is heating, make batter: Whisk together cornstarch, flour, sugar, pepper, and salt in a large bowl. Gradually whisk in cold water until mixture resembles smooth pancake batter. Use tongs to remove chicken from marinade to batter; stir to coat chicken completely. Discard marinade.

4. Working in batches, fry chicken in hot oil for 4 minutes. Transfer chicken to a cooling rack.

5. Increase oil temperature to 375 degrees F (190 degrees C).

6. Working in batches, fry chicken again in hot oil until golden brown and crispy, 3 to 4 minutes. Transfer to a wire rack to drain.

Chef's Notes:

You can substitute 1/2 cup all-purpose flour, 3/4 teaspoon baking powder, and 1/4 teaspoon salt for the self-rising flour.

Serve with Korean Fried Chicken Sauce.

Editor's Note:

The nutrition data for this recipe includes the full amount of the breading ingredients. The actual amount of the breading consumed will vary. We have determined the nutritional value of oil for frying based on a retention value of 10% after cooking. The exact amount will vary depending on cooking time and temperature, ingredient density, and the specific type of oil used.